Fifteen Springs and the Bloom of Sixteen Nights: Two Loves That Long to Be Bound But Cannot

Kunieda Shunki was enjoying a smooth start to his high school life, despite dealing with his yandere-ish childhood friend, Miki Sayaka. However, one day, he gets teased about his relationship with Sayaka by his classmate Chisaki Yuki, who even goes so far as to try to kiss him. To make matters worse, Sayaka witnesses this whole scene and becomes enraged.

The next morning, Shunki tries to clear up the misunderstanding but finds that Sayaka has somehow split into two! Now he’s caught between two jealous versions of Sayaka. Adding to the chaos, Shunki learns that Yuki’s gender has changed to male, leaving him utterly bewildered!

As Shunki investigates this strange phenomenon, he discovers a connection to the legend of the "Everlasting Higanbana" at the temple where Yuki lives. He becomes captivated by the mysterious power of these flowers and finds himself entangled in a new-age love story with supernatural elements, centered around teenage boys and girls!

(Source: Kodansha Lanove Bunko, translated)